1. Field of the Invention
The present invention relates to front rail structures that have controlled thickness that increases the strength of the rail structure from front to rear causing the rail to collapse during a crash event in a progressive manner instead of bending globally.
2. Background Art
Energy absorbing tubular structures are known to be used in vehicles to absorb energy during an impact event. Examples of such energy absorbing tubular structures are disclosed in U.S. Pat. Nos. 6,588,830 and 6,899,195. Energy absorbing tubular structures are seldom subjected to solely axial loading or solely bending loading during an actual collision event. Generally, the actual impact loading of a vehicle during a collision event is a combination of both axial and global bending collapse modes.